This is the 4th book but yes it could also be read as a stand alone. The first 2 takes place a few years before book 3 and this one, and book 3, well in that one we see Jason fall in love and that is how this book starts. Jason leaves Sarah on their engagement party. If I had not read book 3 I am sure I would have been very unhappy with him, but he was in love, and Sarah, wanted stability only.The Sarah that used to be is transformed after The Event into the darling of the Ton, cos else she is just The Girl who lost a Duke. She becomes more snobbish and knows how to cut someone. But she is not unlikable as you see that it's only a facade she puts up to deal with all the whispers and of course she was sad too since she thought they would have been happy.In comes Jackson Fletcher, an old friend who does not like the new Sarah. He wants the old Sarah back, I do like that they have history, and that he is not fooled by a pretty face. But for these two to actually fall in love takes time, a lot of time. I can't say anything more, but they do avoid each other or argue a lot. But he falls, and she needs to let go.And of course there is Blue Raven business going on (he is a spy), there is danger, a sinister plot and Sarah and Jackson is in the middle of it all. We also meet Marcus and Philippa (book 1) again as Philippa is the one who makes Sarah into the Golden lady. And it's always fun to meet up with old couples.Conclusion:It was what I wanted it to be. I also found myself interested in reading a book about her sister, I think it could be fun.